Hi
Is anyone else seeing such things?
Yes, we see the same type of effect.
Our customers are on cybernet-xDSL connections and send their mails through smtp.cybernet.ch. I guess they must have a similar config as the bluewin smtp servers.
The mails simply get lost and never reache the destination mailserver. Sometimes a mail sent to multiple recipients (all on our mailservers) only reaches a few of them. I have no clue what kind of black magic is done on the cybernet smtp servers, but it's very frustrating. I didn't particularly monitor whether mails with and without attachements are affected in different ways.
Another thing I saw is that mails sent to an non-swisscom mailserver on port 25 (non encrypted but authenticated) got a "X-Achtung Spam: " inserted after the headers, causing it to be rejected by some final destination mailservers because the header is invalid (it's preceed by a blank line). That must be because of the smtp-session-highjacking the incumbant is doing.
Anyway, we have been very busy lately to move more and more customers to not only use our mailservers but certainly encrypt their connections as to avoid someone fussing with the payload. I've definitely lost any trust in the smtp service offered by the access providers.
Regards
Jean-Pierre